My work PC is running on Windows 8.1 Pro with 3 monitors (1 x 30" UHD + 2 x 19" UHD). Every time screen get locked, unlocked workspace layout is reset to smaller resolution and a little bit messed up (tables location spacing, lines location change). I see even more drastic effect when ever I connect from home where I have 2 HD monitors, models become messed up much more.
I am currently using evaluation version. Not sure if it is related.
Overall I like Toad Data Modeler, but I am wasting lot of time fixing layout. It is definitely a show stopper for buying it if there is no solution to this problem.